1. Field of the Invention
The present invention relates to a method of adjusting the optical thickness of an optical component such as an optical lens, a plane plate, a prism, a mirror or the like which is made from a material which has the quality of being transparent to the light to be used. The present invention also relates to an optical component of which the thickness has been adjusted by such a method, and to a method of adjusting the position of an optical component such as an optical lens, a plane plate, a prism, a mirror, or the like.
2. Related Art
Generally it is required to process the shape of an optical component at high accuracy. Among the parameters which determine the shape, surface accuracy and thickness accuracy are the items which are very important for almost all optical components. The accuracy which is required for the thickness of the optical component generally becomes more severe, the higher is the resolving power required for the entire optical system, the greater is the numerical aperture of the optical system, and the closer the position of the optical component is to the observation plane or to the image plane. In particular, very demanding accuracy is required with regard to the thickness of an optical component which is used as a so called solid immersion lens or solid immersion mirror.
Furthermore high accuracy is demanded for the thickness of an optical component, if in the same component there are multiple optical paths due to reflection or the like, or if interference of light beams is employed. Naturally, if interference of light beams is employed, the wavelength of the light to be used becomes shorter, the higher is the required accuracy for the thickness of the optical component. As methods for processing the optical surfaces of this type of component, per se known methods such as polishing, pressing, or cutting or the like may be employed.
However, the process accuracy which has recently been required for optical components has reached the sub-micron level, and it has become impossible to provide such accuracy for the optical thickness of optical components with the use of methods such as polishing, pressing, or cutting or the like which have been employed in the past. In the same manner, the positional accuracy which is required when positioning an optical component in the optical system has reached the sub-micron level, and it has become impossible to provide such accuracy when processing a standard mounting surface of the optical component with the use of methods such as have been employed in the past.
The first objective of the present invention is to provide an optical component thickness adjustment method which can attain the optical thickness accuracy of the optical component whose level is sub-micron order.
The second objective of the present invention is to provide an optical component the accuracy of whose optical thickness is controlled to sub-micron accuracy.
The third objective of the present invention is to provide a position adjustment method for an optical component which can control attachment position to better than sub-micron accuracy.